Thermostat.



R. E. HINSON. THERMOSTAT. APPLICATION FILED MAR. a, 1913.

1,094,99 1, Patented Apr. 28, 1914.

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UNITED STATES PATENT OFFICE.

ROBERT E. HINSON, OF HILLSBORO, TEXAS, ASSIGNOR OF ONE-HALF TO SIDNEY QUAYLE, 0F HILLSBORO, TEXAS.

THERMOSTAT.

To all whom it may concern:

Be it known that 1, ROBERT E. HINSON, a citizen of the United States, residing at Hillsboro, in the county of Hill and State of Texas, have invented new and useful Improvements in Thermostats, of which the following is a specification.

The invention relates to thermostats, and has for an object to provide a device for automatically regulating temperatures.

The invention embodies, among other features, a thermostat operable in conjunction with an electric current or the like to control the amount of heat produced by a radiator or other heating-medium, in a room or receptacle.

The invention is particularly adaptable for use in connection with incubators and in which, when it is desired to hatch eggs, the temperature should, if possible, be kept constant and not permitted to fluctuate.

In the further disclosure of the invention reference is to be had to the accompanying drawings, constituting a part of this specification, in which similar characters of reference denote corresponding parts in all the views, and in which Figure 1 is a front elevation of the device, the cover of the casing having been broken away to disclose the underlying structure; Fig. 2 is a horizontal sectional view taken on the line 22 in Fig. 1; Fig. 3 is a vertical sectional view taken on the line 3-3 in Fig. 1; and Fig. 4: is an enlarged vertical sectional view taken through the heater casing and showing the heating element in side elevation.

Referring more particularly to the views, I provide a supporting plate 10 having a longitudinal slot 11 in which is mounted to slide a block 12, a screw 13 being arranged to pass through the block and through the slot 11 and having threaded connection with a plate let in the rear of the supporting plate 10 and which is slidable in guideways 15 provided on the rear of the plate 10 so that when the screw 13 is screwed up on the block 12 the block will be held in rigid position at any desired point along the slot 11.

A series of graduations 16 are provided on the face of the supporting plate 10 and a pointer 17 projects from the block 12, the said pointer being preferably made of a flexible current conducting material and adapted to operate over the graduations 16 Specification of Letters Patent.

Application filed March 8, 1913.

Patented Apr. 28, 1914.

Serial No. 753,112.

when the block is advanced in the slot 11, the said graduations denoting various degrees of temperature. A contact pin 18 is also arranged to project from the block 12 and terminates in a point 19 normally engaged by the pointer 17 a distance from the free end thereof and an electric wire 20 has connection with the pointer 17 and a suitable heater 21, a second wire 22 having connection with the contact pin 18 and the heater 21 so that when the electric current is turned on to the heater, the engagement of the pointer 17 with the contact pin 18 will complete the circuit and produce heat at the heater.

Mounted to slide on the supporting plate 10 is a rack bar 23, the upper end of which is adapted to engage the free end of the pointer 17, and journaled on the supporting plate 10 is a toothed wheel 24 meshing with the rack bar 23 and which is keyed to rotate with a shaft 25 extending into a casing 26 in which is mounted a sensitive member 27, preferably formed of two pieces of metal, one piece of metal arranged to lie upon the other, with the outer piece of metal sensitive to heat, the said member 27 being coiled in the nature of a spring, with the inner end secured to the shaft 25 and the otherend of the member secured within the casing 26.

Now assuming that the entire device described is mounted in a suitable receptacle, if it is desired to retain the heat in the receptacle at a temperature of ninety degrees, the block 12 is slid upwardly on the supporting plate 10 until the pointer 17 indicates ninety degrees on the graduations 16. The current of the electric heater is now turned on and inasmuch as the pointer 17 normally engages the contact pin 18, the electric circuit to the heater will be closed and the receptacle will become heated by the heat produced. Now as the receptacle becomes heated the sensitive member 27 will tend to expand, thus imparting rotation to the shaft 25 and causing the toothed wheel 24 to rotate therewith. Now inasmuch as the toothed wheel 24 meshes with the rack bar 23 an upward movement will be imparted to the rack bar and if the receptacle should become heated beyond seventy degrees the upper end of the rack bar will engage the free end of the pointer 17, thus moving the pointer slightly upward and out of engagement with the contact pin. It will, therefore, be seen that when this is accomplished the circuit will be broken and the production of heat at the heater will be discontinued. l/V hen the temperature in the receptacle lowers, the member 27, in tilting, will reverse the rotation of the shaft 25, thus through the medium of the toothed wheel causing the rack bar to move clownwardly on the supporting plate and permitting the pointer 17 to re'e'ngage the con tact pin 18 and recomplete the circuit to the heater so that new heat will be furnished.

From the foregoing description it will, therefore be apparent that through the op eration of the device in the manner mentioned, the temperature in the receptacle will be at all times normal and, if the temperature should go above normal the production of heat in the receptacle will be dis continued, but will be immediately recontinued when the temperature falls below normal or below the required amount of heat in the receptacle.

Having thus described my invention, 1 claim:

In a device of the class described, the combination with a slotted supporting plate, of

a block slidable on the plate and guided in the said slot, a pointer carried by the block, graduatio-ns on the supporting plate and over which the said pointer is adapted to operate, means for securing the said block in a rigid position on the supporting plate, a contact pin projecting from the block and normally engaged by the said pointer, a rack bar mounted to slide on the said supporting plate and adapted to engage the said pointer and move the same out of engagcment with the contact pin, a shaft journaled on the supporting plate, a casing carried by the supporting plate and into which the shaft extends, a toothed wheel keyed to rotate with the shaft and meshing with the said rack bar to actuate the same, and a sensitive meml er carried in the said casin and having connection with the said shaft for imparting rotation thereto when the said member is subjected to heat.

In testimony whereof I allix my signature in presence of two witnesses.

ROBT. E. HINSON.

lVitnesses O. G. Hmson, R. J. HINSON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

